Tongs



' 7, 1945. Y J. A. GAMMEF. 2,381,045

TONGS Filed April 14, 1944 5- Sheets-Sh eet mmvrcm Jon" 4 60min BY Jmsw{MM Aug. 7, 1945. J. A. GAMMEL 2,381,045

TONGS Filed April 14, 1944 5 Sheets-Sheet 2 INVENTOR vhw 46AMME4 BIZ/41WW ATTOENEYJ' Aug. 7, 1945. J. A. GAMMEL TONGS Filed April 1-4, 1944 3Sheets-Sheet 3 INVENTOR. JOHN 14 GHMMEL Patented Aug. 7, 1945 TONGB JohnA. Gannnel, Seattle, Wash., asslgnor to Isaacson Iron Works, Seattle,Wash, a corporation of Washington Application April 14, 1944, BerlalNo.531,019

5 Claims. (Cl. 2941l0) This invention relates to tongs and it hasreference more particularly to improvements in tongs of those kindsdesigned to lift extremely heavy shafts or ingots; for example, a pairof tongs suitable for handling metal shafts of from eight to eighteeninches in diameter and from eight to sixteen feet long and weighing manyFor better understanding of the present invention, it will here beexplained that it is a usual thing at this time to handle large, heavyhot shafts and hot ingots by means of tongs that are somewhat similar inconstruction and mode of use-to those embodied by the present invention.Present-day tongs usually comprise two sets of jaw levers suspended bysuitable linkage and a cable operating over sheave blocks from atraveling crane or carrier. jaw levers are crossed and pivotally joined.and are" equipped at their lower ends with coacting hook shaped lawsdesigned to be openedapart and due to the character and connection-ofthe linkage attached to their upper ends. Such laws Each set ofautomatically retain their grip on the shaft so long as it is held insuspension thereby.- when the shaft as thus held by the'tongs, is.lowered onto a support, and the tongs are then lowered an additionaldistance after the shaft has come to rest, the weight of the linkageattached to the.

I in open position, they may be liftedin the clear of the released shaftand they may be lowered onto another shaft. However, it is required thatthey be unlocked in order that they may then be closed about the shaftto pick it up.

. In view of the work involved, the difliculty encountered when red hotshafts are being han-' died, and the time wasted in the operations ofmanually releasing or looking thetongs for the operations of picking upand placing the tongs in position. it has been the principal object ofthis.

invention to provide novel means in combination with the sets of tonglevers whereby the looking and releasing of jaw! isautomaticallyaccomplished through'the raising and lowering 'of the tonesfrom and against the shaft or other object that is to be handled.

more specifically stated, lt is the object of this invention to provide-a set of lifting tongs,

- equipped withautomatic locking. and release devices wherebyanoperation of colnpletelyopen-- ing the laws apart after a shaft hasbeen deposited thereby causes the devices to operate to retain the lawsin a, partially open position so that they may be lifted clear of thedeposited shaft and held in that partially open position permittingtheir being applied over another shaft. The invention provides furtherthat the complete opening of the tongs after application over anothershalt, will 'so-actuate the automatic means that when the tongues areagain lifted, the jaws lvivillbe permitted to close about the shaft tobe fted.

. Still further objects of the present invention are to be found in thedetails of construction of parts of the automatic locking devices and intheir mode of operation as will hereinafter be fully described. v

In accomplishing these and other objects of the invention. I haveprovided the improved details of construction, the preferred forms ofwhich are illustrated in the accompanying drawinss. wherein- Fig. 1 is aperspective view of a set of tongs embodying the improvements of thepresent invention, the jaws thereof bein shown in the partly openposition in which they are locked when being lowered over a. shaft thatis to be picked up. p v

Fig. 2 is an end view of the set of tongs.

Fig. 3 is a side view of the same.

Fig. 4 is a view in which a part of one of the jaw levers is broken awayto better showthe automatic locking devices.

Fig. 5 is a top view of a part of one of the jaw levers showing thelocking devices as applied thereto.

Fig. 6 is a side view of the parts as seen in Fig. 5 with certain partsbroken away for better illustration.

Fig. '7 is a similar'view showing the automatic devices in positionlocking the laws open.

Fig. 8 is a perspective view of the latch plate and latch dog thereon asapplied to one of the jaw levers of the set of tones.

Fig. 9 is a top view of the latch wheel or'gear.

Fig. 10 is a cross section taken on line Ill-J0 I in m. 9.

Fig. 11 is an end view of the gear.

Figs.- 12 to l8 inclusive show the successive positions of the latchdevices as actuated incident to lowering the open tongs onto a shaft,releasing the latch, closing the tongs to pick up the in the clear ofthe deposited shaft and ready for I V The present lifting tongs, asshown best in" I'll. Loomprisetwo sets of laws, each'jaw set Icomprising a pair of crossed levers ill and Illa,

that are pivotally joined in their crossed relationship by a pivot boltII. The two levers of each set of laws are formed at their lower endswith hook shaped, cooperatively arranged jaw portions II:

jaws. The end of the latch lever 38 opposite the tooth ll has one end ofa spring 39 attached thereto and the springis attached at its other end,funde'rtension, to, an extension is at the adapted to-be closed towardeach other about the opposite sides of a bar or shaft these two portionsand the assembled levers are secured pivotally together by the pivotbolt. The levers II and "a. of each setof jaws are substantially of thesame length and at their outer ends, each is pivotally attached as at "atoo. block It and the blocks It, at the ends of lever of the two sets oftongs that extend in the same direction are joined by horizontal bars orshafts l8 and these bars are attached, each by a pair of links or strapsII, to a central hinge member to which a suspending cable II isattached. It is to be understood that the two sets of jaws embodied inthis device, as seen in Fig. 1, are

raised and lowered as'a unit by the cable II. It

is to be explained'aiso that, considering the device as so iardescribed, and without the present automatic locking devices appliedthereto, the jaw portions of the two sets of t l-(gs, due to theirweight and manner of connection with the cable,- would close togetherincidentto lifting the device, and would be fully opened apart iflowered against a supported shaft after the fashion indicated in Fig.13, but would not remain open so as to permit them from one shaft andlowered over The present automatic devices means for locking the shownbest in Figs. 4 to 8 inclusive, wherein it is another.

shown that a vertically disposed plate II is welded or otherwise fixed,to the top edge of the lever ll of each jaw set near its jaw portion.Thus, are two of the automatic locking devices used. However, since eachis like the other in construe tion and mode of use. only one will bedescribed in detail and it will be understood that this de: scriptionapplies equally to both. extends upwardly and between the spaced sidemembers of the bifurcated lever the longitudinal planes of the twoRotatably that extends between theof the lever arm-10a, is a latch ll,shown in top view in Fig; 9. At one wheel body is formed with a M and atits other end has a three toothed oppositeiY facing ratchet ll. Theratchets I4 and are spaced apart and their teeth lie, respectively inplanes at opposite sides of the plate II, which. as shown best in Fig.4, has one vertical edge thereof arcuately ,curved about the axis of.the

.pivot pin H as a center. Thus,

and closing action of thejaw levers, edge retains the same relationshipto the gear.

On one side of the plateas seen best in jaw levers.

spaced side members end, this Fig. 8, a-latch lever or pawl jt'ismounted by.

a-pivot bolt 81. One end of this pawl lever is formed into an upwa-facing tooth is directedtoward the outer end of-lever Ila,

arcuate edge of plate with the teeth of the-ratchet wheel 8 in thehinging orfopening and closing actions-of the to be lifted into theclear 7 provided as a. jaws in open position, is

for the set tongs as shown in Fig. 1, there The plate 30,

its and lies in gear or wheel six toothed ratchet in the openingtheplate I upper end of plate 30 .to'pull that end of the lever up againsta stop' lug Al on the side of plate II, thus to hold the tooth 38 insuch position that in closing the jaws together, it will engage a toothof the ratchet is to advance it one interv l. th t is, one sixth of aturn. With 'the' 0105- his actions of the'set of jaws, this toothyieldsand passes over the teeth of wheel is without.

-the action of the pawl 36. e

' It is also to be noted that there is a lug 4sformed on that side faceof the plate 30 opposite that face on which lug u is formed. This ing.45, as observed in Fig. .7, is in position to 'oftheshafttolock mountedon a cross axle or pin 3|,

-- plate II; the

' and may be lowered over the shaft 8.

adjacent the the tongs are permitted to be lowered against 8| andadapted to engage port, for example, as shown lever armsand linkage beengaged by the teeth of the'ratchet and when it is engaged by one of theteeth, as it a is shown iii-Figs. 4 and 'l, and considering that thelatch gear is held by pawl ll against reverse rotation, the stop andratchet 35 will operate to prevent the closing of the'jaws together,thus holding the tongs in an open position that permits them to belifted clear of a shaft or to be placed over ashaft.

With the understanding that with each closing action of. the jaws from afully open position, the tooth It of latch lever it causes the latchgear a to be advanced one sixth of a turn, it will be understood thenthat each alternate rotative advancement of the gear will cause a toothof the ratchet 8| lock with the lug ll to hold the jaws open. Therelative positions of parts of the automatic latch devices arediagrammatically shown in Figs. 12 to 16 for the operations beginningwith the lowering of open tongs over a shaft, then the additionallowering of .the tongs after the shaft has been deposited on a supportto cause the complete opening of the-jaw levers latch devices; then, insuccession, picking up the shaft, completely lowering the tongs after,deposit v the jaws open, and finally raising the open tongs from theshaft. Explanation of the yiews of Figs. 12 to 16 is as follows: i Y

First it will be stated that the jaw levers have three definitepositions: first, the open position, at which the latch devices lock thelaws for application to or from a shaft, as seen in Figs. 12

and 16; second, a fully'open position to whichthey can be moved bylowering the tongs down against the shaft while it is resting on a supinFigs. 13 and 15;

third, the closed position. at which thejaws close about the obje'ct tolift it. All of these operations of the jaw levers are effected throughthe linkage connecting them with the suspending cable. e I

Now, with the parts asseen in Fig. 12, with thelstch gear It in suchposition that a tooth of the ratchet ll engages the stop I! on Then, if

the shaft to their fullest extent, the weight of to be brought intoposition to and release the jaws will be held in open position swingsthe levers to their )7 full open position of Fig. 13. This action causesthe tooth 38 of latch pawl 36 to swing from the position shown in Fig.12, up against a tooth of rachet 34 to rotate the ratchet one-sixth of aturn, and to cause the ratchet 35 to likewise rotate and the parts toassume the positions shown in Fig. 13, at which it is noted that teethof ratchet 35 are in the clear of path of travel of the lug 45 on plate30. Therefore, when the tongs are lifted to close them about the shaft,as they are shown in Fig. 14, the plate 30 swings the stop 45 down belowthe ratchet 35 and the yieldable pawl 36 ratchets over teeth of ratchet34;

the latch gear being held against reverse turning by pawl 4|.

When the shaft, as held by the tongs in Fig. 14, is lowered onto asupport and the jaw levers again actuated to their fully open position,as

shown in Fig. 15, the relative upward swinging of plate 3|] past thelatch gear 33 causes the pawl tooth 38 to engage and again rotatablyadvance the latch gear 33 one-sixth of a turn and to position the lug 45above the gear and to rotatably advance gear 35 into locking position,as seen in Fig. 15. Then when the tongs are lifted, a tooth of gear 35engages the stop lug 45 on plate 30 and thus locks the jaws againstclosing and the tongs may be lifted clear of the shaft.

Such automatic locking mechanism may be employed on single sets of jawsor on double sets as here shown, and may be applied to tongs of varioussizes and for various uses, but are especially useful when the part orobject handled is red hot or where manual operation of latching devicesis impractical or impossible.

Having thus described my invention, what I claim as new therein anddesire to secure by Letters Patent is:

l. Tongs of the character described comprising crossed, pivotally joinedlevers having lower end jaws designed to cooperatively grip an objectthat is to be lifted and having connections at their upper ends withlifting means through which a lifting operation causes jaw closingforces to be applied to the levers, and whereby the jaws will be movedto a fully opened position when the tongs, with jaws in open position,are brought to rest upon an object and the weight of the tongs isunsustained by the 1ifting connections; and an automatic latchingmechanism for retaining the jaws at a predetermined, partially openposition for their application to an object; comprising a one directionlatch gear mounted on the outer portion of one of the pivoted levers, astop and a pawl mounted on the inner portion of the other lever; thepawl being operable with each complete opening of the jaws to rotatablyadvance the latch gear for the holding engagement therewith by the stopwith alternate complete opening operations.

2. Tongs of the character described comprising crossed, pivotally joinedlevers having lower end jaws designed to cooperatively grip an objectthat is to be lifted and having connections at their upper ends withlifting means through which a lifting operation causes jaw cilosingforces to be applied to the levers, and a latching mechanism applied tothe levers and adapted to be automatically set to retain the jaws at apredetermined open position for application to an object; said latchingmechanism comprising a ratchet gear mounted on one lever to turn in onedirection only, a Stop on the other lever movable past the said ratchetgear with each adjustment of the jaws between closed and open positions,and other means on the last mentioned lever operable by the saidadjustments of the jaws to advance the ratchet gear to successivepositions for the passage of the stop device to permit the closing ofthe jaws, and for its engagement to hold the jaws in that open positionrequired for their application to an object.

3. Lifting tongs of the character described comprising crossed pivotallyjoined levers having lower end jaws designed to cooperatively grip anobject that is to be lifted and having connections at their upper endswith a lifting means through which lifting operations, causes jawclosingforces to be applied to the levers; an automatically operablelatch mechanism associated with the levers and adapted to be set inposition for limiting the closing action of the jaws beyond apredetermined open position required for the application of the jawsabout an object; said mechanism comprising a latch gear wheel rotatablymounted on one of the jaw levers to turn in one direction only,-andhaving two sets of ratchet teeth thereon, a stop lug and a pivoted. pawlmounted on the other lever; said pawl being adapted to act against theteeth of one set to rotatably advance the latch gear with eachadjustment of the jaws to a fully open relationship to thereby, onalternate advancements of the latch gear, locate a tooth of the otherset of ratchet teeth in position for engagement by the stop to limit theclosing adjustment of the jaws to that open position required forapplication of the jaws to an object.

4. Lifting tongs of the character described comprising crossed pivotallyjoined levers having lower end jaws designed to cooperatively grip anobject that is to be lifted and having connections at their upper endswith a lifting means through which lifting operations cause jaw closingforces to be applied to the levers; and an automatically operable latchmechanism associated with the levers and adapted to be set in positionfor limiting the closing action of the jaws to a predetermined openposition required for application of the jaws about an object and to bereleased therefrom; said mechanism comprising a latch gear wheelrotatably mounted on one lever and having two sets of ratchet teethformed thereabout in opposite direction, a pawl on the lever yieldinglyengaging the first set of ratchet teeth to prevent reverse rotation ofthe wheel, a stop and a pawl mounted on the other lever, and said pawlbeing operable against teeth of said ratchet incident to opening andclosing action of the jaws to rotatably advance the latch gear through adefinite interval and with alternate advance movements to cause teeth ofthe second set of ratchet teeth to be positioned for engagement by saidstop to check the jaws against closing beyond that open positionrequired for their application to an object.

5. Tongs as recited in claim 4 wherein one lever is bifurcated and theother lever is pivotally contained between the opposite sides of thebifurcated lever, and'wherein the latch gear and its locking pawl isrotatably contained between the bifurcated parts of the lever; and saidpawl and stop of the other lever are mounted on a plate that operatesbetween the sides of the bifurcated lever.

JOHN A. GAMMEL.

